Solid matrix priming of seeds with microorganisms and selected chemical treatment

ABSTRACT

In the process of the invention, the seed to be treated, a predetermined amount of solid matrix material and a predetermined amount of water are admixed and the mixture allowed to stand, preferably in a container which allows entry of air but which reduces evaporation losses, for example, a closed metal container with a small top opening, for a time and at a temperature sufficient to enhance resultant plant vigor, i.e., enhance emergence, growth of yield characteristics, but short of that which would cause the seed to sprout. Faulty seeds may be separated by size and systemic resistance to disease can be induced.

RELATED CASES

This application is a divisional of U.S. patent application Ser. No.08/854,500, filed May 12, 1997, now U.S. Pat. No. 5,974,734, which is acontinuation-in-part of U.S. application Ser. No. 08/369,308 filed Jan.6, 1995, now U.S. Pat. No. 5,628,144, which is a continuation-in-part ofU.S. application Ser. No. 07/975,401; filed Nov. 10, 1992, U.S. Pat. No.5,544,745 which is a continuation-in-part of U.S. application Ser. No.07/503,826, now abandoned, which is a continuation-in-part of U.S.application Ser. No. 07/440,470, filed Nov. 20, 1989 now abandoned,which is a continuation of U.S. application Ser. No. 07/175,934, filedMar. 30, 1988 now abandoned, which is a continuation-in-part of U.S.patent application Ser. No. 07/034,812 filed Apr. 3, 1987, entitledSOLID MATRIX PRIMING OF SEEDS, now U.S. Pat. No. 4,912,874.

BACKGROUND OF THE INVENTION

This invention relates to the conditioning of seeds, such as forexample, by priming, chemical treatment and biological treatment and tothe use of biologically treated seeds to recondition land and improveplant productivity.

Seed priming or osmoconditioning are terms to describe a knownpre-sowing hydration treatment developed to improve seedlingestablishment (Heydecker and Coolbear, 1977, Seed Science and Technology5:353-425), (Khan, et al., 1980/81, Israel J. Bot. 29:133-144) and(Bradford, 1986 HortScience 21:1105-1112).

In seed priming, the seeds are placed in an aerated osmotic media ofknown water potential. In this process, the osmotic solutions induce awater potential that prevents the completion of germination (radicleemergence). Seeds are, however, able to imbibe and complete the earlyphases of germination under limiting water content conditions. Theduration of the priming treatment has been reported to be from less than24 hours (Guedes and Cantliffe, 1980, J. Amer. Soc. Hort. Sci.105:777-781) to several weeks (Khan, et al., 1980/81, supra) and isdependent on species, cultivar and even seedlot. Seeds are then driedback. After priming, seeds can be sown with existing planters. Resultsobtained from priming different crop seeds have been reviewed byBradford, 1986, supra. In general, seedling emergence of primed seeds isearlier and more sychronous than dry sown seeds. Improvements in plantgrowth and yield characteristics have also been documented.

In the prior art priming processes, several different osmoticums havebeen used to achieve the water potential for priming including highmolecular weight (MW of 6000-8000) polyethylene glycol (PEG) and/orinorganic salts (Heydecker and Coolbear, 1977, supra). After priming,the seeds are removed from the solution used for establishing the waterpotential before being dried back.

Several technical and logistical difficulties have been encountered withthe prior art priming techniques. For example, osmotic solutions requirecontinuous aeration and in general, a large volume of priming solutionis required per quantity of seeds. Reductions in percentage seedlingemergence have been reported with the use of inorganic salts(Brocklehurst and Dearman, 1984, Ann. Applied Biol. 102:585-593). Arelatively high concentration of PEG in solution is viscous and has lowoxygen solutibility and diffusivity (Mexal, et al., 1975, Plant Physiol.55:20-24).

An alternative to the use of solutions is to prime seeds in a solidmedium. A solid material should have a high water holding capacity andallow seeds to imbibe. Peterson (1976, Sci. Hort. 5:207-214) described aprocedure to prime onion seeds in a slurry of PEG 6000 and vermiculite.A ratio of three to four parts vermiculite moistened with PEG solutionwere mixed with one part seed. Although this technique overcame the needfor aeration, he reported that the seeds were difficult to separate fromthe vermiculite. Methods have been described to increase the seedmoisture content of large-seeded vegetables prior to sowing (Bennett andWaters, 1984, J. Amer. Soc. Hort. Sci. 109:623-626 and 1987, J. Amer.Soc. Hort. Sci., 112:45-49). Seed moisture content of lima beans(Phaseolus lunatus) and sweet corn (Zea Mays) was increased by combiningseed, vermiculite and a known amount of water in a closed container.This mixture was incubated and then the vermiculite sieved away prior tosowing the hydrated seed. Seedling establishment was improved by thepre-sowing treatments for both crops.

Inoculation of seeds with bacteria or chemicals prior to planting isknown in the art. For example, United Kingdom patent specification849,210 discloses inoculating seeds under reduced pressure to enablepenetration of the bacteria under the coat of the seed and thus survivalof the bacteria for a period of time. This procedure is expensive andappears to be limited in the range of bacteria that can be inoculatedinto seeds.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide a noveltechnique for priming seeds.

It is a still further object of the invention to provide a noveltechnique for inoculating seeds.

It is a still further object of the invention to provide a noveltechnique for inoculating soil.

It is a still further object of the invention to provide a noveltechnique for inoculating soil for bioremedial purposes.

In accordance with the above and further objects of the invention, asolid phase media is used to prime seeds. The solid phase media includesa solid matrix that provides a structure to hold water and allow gasexchange. Chemical treatment and addition of microorganisms may beaccomplished during priming. The seeds may be used to inoculate soilwith bacteria such as for example, bacteria useful in agriculture or tobreakdown contaminants in the soil and facilitate plant uptake ofcontaminants from soils, such as for example, radionuclides.

The solid matrix holds water with an appropriate water potential toinitiate and maintain metabolism prior to germination. The temperatureand aeration are at a level that reduces damage.

The seeds are then dried back and the drying back may be performed inmore than one phase with aeration and moisture control interrupting thedrying operation to promote healing. In one embodiment, the seeds areseparated from the matrix after being dried although, in otherembodiments, the seed in the matrix may be used for planting,particularly in the case of small seeds which require added matrixmaterial for efficient use in planters or in the case where the matrixaids in the development of beneficial microbes or the beneficialapplication of chemicals to the seed.

From the above description, it can be understood that the method,mat5rix and seed of this invention have several advantages such as: (1)there is a synergistic relationship with inoculation by microorganismsor the use of chemical treatment in the priming; (2) superior synchronyof emergence and speed of germination are provided; (3) a higher yieldis obtained from the seeds; and (4) the priming provides a certainmeasure of synchronism with other techniques such as the coating ofseeds for protection.

SUMMARY OF THE DRAWINGS

The above noted and other features of the invention will be betterunderstood from the following detailed description when considered withreference to the accompanying drawings in which:

FIG. 1 is a block diagram of a priming system in accordance with anembodiment of the invention;

FIG. 2 is a diagrammatic view of a portion of a mixing system used inthe embodiment of FIG. 5;

FIG. 3 is a diagrammatic view of another embodiment of mixing systemused in accordance with the embodiment of FIG. 1 instead of using theembodiment of FIG. 2;

FIG. 4 is a diagrammatic view of a conditioning system used in anembodiment of a portion of FIG. 1;

FIG. 5 is a diagrammatic view of a drying system used in accordance withthe embodiment of FIG. 1;

FIG. 6 is a diagrammatic view of another embodiment of drying system inaccordance with the invention;

FIG. 7 is a diagrammatic view of still another embodiment of dryingsystem used with the invention; and

FIG. 8 is a diagrammatic view of a separator assembly according to theinvention.

DETAILED DESCRIPTION

To prime seeds, the seeds are incorporated in a solid phase matrixcomprising finely divided nonpathogenic, water-holding solids.Preferably, the matrix material, not including the seeds, is in suchproportion and distribution with respect to the seeds so that the seedsurfaces are sufficiently aerobic to favor aerobic metabolism of theseeds and of beneficial microorganisms, to deter the growth ofunfavorable facultative anaerobes or anaerobic microorganisms and topermit proper metabolic changes. In most cases, this is accomplished byusing the proper volumetric ratio of seed to matrix material andaeration.

The volumetric ratio of seed to matrix material should be for practicalreasons in the range of one volume of seed to 120 of matrix material atone extreme to one of matrix to ten of seed at the other extreme.Preferably, a one to one ratio of seed to matrix is generally favorablebut the ratio may be lower as in cases where seed exudation andgermination inhibitor removal are significant seed priming and treatmentobjectives and higher such as when microbial inoculation calls forretaining exudates. In cases where the seed to matrix mixture contains asubstantially larger volumetric ratio of seed over matrix, properaeration during priming can be maintained through a combination ofmechanical mixing and aeration of the seed plus matrix mass or moreaeration.

The matrix material, when containing the water necessary to prime theseeds in question, should be sufficiently friable, nonclumping etc. sothat, when desired, it can be separated from the treated seeds aftertreatment without damage to the seeds. The particle size of the matrixmaterial is not unduly critical as long as surface area is adequate, butfor mechanical reasons should be smaller or larger than the seed beingtreated, usually less than 20 mesh and preferably substantiallydifferent. Typically, a material less than about 60 mesh is preferred;for example the Agro-Lig described hereinafter was 90%/wt less than 200mesh, the soft coal was less than 60 mesh.

One type of matrix is formed of organic solids, for example acarbonaceous, preferably a lignateous solid which has a largeequilibrium water potential and preferably has an osmotic potentialcomponent which is at least about 90% and preferably greater than 95% ofthe total water potential, measured as described below. Examples of suchmaterial include coal, especially soft coal, lignateous shales such asthe leonardite shale, sold as Agro-Lig, and sphagnum moss.

Another type of matrix material is inorganic such as calcined claymineral, vermiculite and perlite. To achieve a practical cost-effectivesystem using an inorganic particulate matter as the matrix, the bulkdensity of a matrix of that inorganic particulate matter is preferablyabove 0.3 grams per cubic centimeter. In this specification, bulkdensity means the weight in grams of a given volume of particulatematerial divided by its volumes in cubic centimeters. When usinginorganic materials, the water potential is generally determined notprimarily by osmotic potential but primarily by matric potential.

In the process of the invention, the seed to be treated, a predeterminedamount of solid matrix material and a predetermined amount of water areadmixed and the mixture allowed to equilibrate, preferably in acontainer designed to provide aeration but which reduces evaporativelosses, for example, a closed metal container or bag, for a time and ata temperature sufficient to allow the seeds to imbibe water from thematrix and maintain or change a prescribed water content equilibriumtemperature and aeration sufficient to enhance resultant plant vigor,i.e., enhance emergence, growth or yield characteristics, but short ofthat which would cause the seed to sprout. Particularly useful materialsfor the matrix are coal related materials, calcined clay, diatomaceousearth vermiculite, sawdust, perlite, peat/moss, corn cobs and graindust.

As in solution priming, the equilibrium amount of water for the systemto prime the seed is dependent on the specific seed variety, its stateor condition, and the water potential of the solid matrix material.Typically the solid matrix material should have a water potentialbetween about -0.5 to about -0.2 megapascals at equilibrium with theseeds. With control of temperature, this range may be extended to -0.2to about -3.6. The exact conditions depend on the objectives and speciessuch as destruction of inhibitors or physiological or physicalblockages. The seed priming art to some extent is still empirical, andwhile typical water amounts and media water potentials for given seedtypes are already generally known from the solution priming art andsolid state matrix priming experiments for some seeds, it is frequentlybest to test a small sample of a new seed over a readily determinedrange of water potentials and temperatures to determine what conditionsof temperature, water potential and time cause appropriate imbibing ofwater by the seed and resultant pregermination events. After thispriming, the seeds may be dried to a resting or dry storage state, withor without the matrix material. Treatment with beneficial microbes orchemical treatment may be before, during or after priming.

In one process of the invention, a known weight of seed is wet withabout 25% by weight of water. The total water utilized is typically inthe order of about one liter per kilogram of seed but varies with seedsize and seed condition. The seed is mixed with the dry, flowable,particulate solid matrix material and water with appropriate chemicalsor biologicals added so as to wet seeds and particulate matrix materialuniformly. After the predetermined amount of water for priming isadmixed with the coated seeds, the mixture is held at a predeterminedtemperature for a time sufficient to allow the seeds to maintain adesired moisture content equilibrium, usually one to about fourteendays. In other processes, the water, seed and matrix material are mixedin a continuous flow or batching blending system. The ratio of water mayalso vary substantially from 25 percent of the seed weight.

The seeds that can be treated can be virtually any seed, including mostvegetable crops, ornamentals and agronomic crops. Included are cucumber,lettuce, carrot, onion, melons, sweet corn, tomatoes, eggplant, peppers,bean radish, squash, pea, flower seeds, alfalfa and soybean. Severaldifferent apparatus can be used for these procedures. One such apparatusis described below.

In FIG. 1, there is shown a block diagram of a priming system 10 havinga mixing assembly 12, a conditioning assembly 14, a drying assembly 16,a separating assembly 18 and a chemical treatment and inoculationassembly 20. In this system, seeds and a matrix are: (1) mixed togethereither with no chemical treatment or inoculation of the seeds or withchemical treatment and/or inoculation of the seeds; (2) conditioned; (3)dried back; and (4) in some embodiments, the matrix medium and seeds areseparated.

The chemical treatment or inoculation generally takes place in thechemical treatment and inoculation assembly 20 which may communicatewith the mixing assembly 12, the conditioning assembly 14, the dryingassembly 26 or the separating assembly 18 or none of them. The mixedmatrix, seeds and water are utilized for pre-germination metabolism,after which the seeds may be dried back in the drying assembly 16although from time to time the drying assembly 16 and and conditioningassembly 14 are used intermittently for staged conditioning and drying.The drying assembly 16 may communicate with the separating assembly 18to separate the matrix from the seed in some embodiments although suchseparation is not always required. The treated seeds may be stored andused later or immediately utilized.

Not all seeds are subject to chemical treatment or inoculation, andthus, the chemical treatment and inoculation assembly 20 is not alwaysused. However, in some embodiments, the seeds may be chemically treatedor inoculated with microbes prior to being mixed in the mixing assembly12 with water and matrix, or in the alternative, such treatment may beapplied in the conditioning assembly 14, the drying assembly 16 or laterafter preconditioning.

In some embodiments, the beginning stages of metabolism occur until thebeginning of germination as indicated by the emergence from the seedhull of embryo, at which time inoculation with beneficial microbes takesplace. After the inoculation, the seeds may be returned to theconditioning assembly 14 for healing to be restored to a pre-germinationstage without full germination and be dried back for later use.

In FIG. 2, there is shown a schematic view of a mixing assembly 12having as its principal parts a water source 26, a solid matter source28 and a rotatable mixing tank 34 connected together so that the sourceof water or water plus additives such as potassium nitrate and the solidmatter source 28 such as matrix material and seeds communicate with arotatable mixing tank 34 which combines the ingredients into the propermixture for oxidation, temperature control and water potential control.All of these sources may pre-mix the solid matter and moisture and thenapply it to the mixing tank or they may be individually applied orcombined to pairs and applied or combined with treatment material or thechemical treatment material may be applied to any of the ingredientssuch as the source of water or the source of matrix or to the seedsalone.

The source of water 26 includes a meter 30, a source of water 32, and insome embodiments a pump 42 connected together so that a metered amountof moisture may be applied to a mixing mechanism, which in theembodiment of FIG. 2, is a rotatable tank. It is adapted to receive thewater and solid matter and then to be rotated for thorough mixing. Ofcourse, other embodiments may be utilized such as a tank with internalstirring means rather than a rotating tank and/or connections withrotatable universal joints that rotate with the rank rather thanconnectors at the center of rotation.

The solid matter source 28 includes a seed and solid matrix conveyor 36,a source of seeds 38, and a source of matrix material such as clay 40.These ingredients may be premixed or moved one-by-one into the tank 34by an auger or forced air flow or gravity or any other means.

In FIG. 3, there is shown an embodiment of water source 26A having atank of water 32A which contains water and potassium nitrate. The tankcommunicates with a pump 42 and a meter 30 in a conduit 31 for supplyinga mixture of liquid ingredients which may include additives such aspotassium nitrate to condition for light sensitivity or chemicalsbeneficial to seed treatment or being antifungal or antimicrobial orwith beneficial microbials for inoculation and in some embodiments,nutrients therefore.

With this arrangement, a carefully metered amount of water may besupplied to provide the correct matrix potential. In some applications,a small amount of water is supplied and then the supply is disconnectedfrom the tank which is rotated for mixing and then further water issupplied. The intermittent stationary portions of the tank may beutilized to also add more dry matter if desirable so that the mixingtogether may proceed with stepped amounts of dry matter and water.

In FIG. 4, there is shown a schematic diagram of another embodiment ofmixing assembly 12A having a source of seeds 38A, a source of dry matter40A, the source of water and liquid additives 26A, a mixing section 58,and a mixture agitator and transporter 62. The source of seeds 38A andthe source of dry matter 40A each include a different one of the hoppers50 and 52 respectively for containing bulk seed and dry matter such asmatrix. At the bottom end of each, there is a corresponding one of theseed conveyors 54 and conveyor 56 which are aligned directly in the lineof gravity underneath the seed and matrix hoppers 50 and 52 respectivelyand are drivable at controlled speeds independently to transport fromthe hoppers controlled amounts of material for mixing in the mixingstation 58.

The bottoms of the hoppers are adjustable and the speed of thecontainers are adjustable so that the ratio of mixing may beproportional in accordance with the type of seed and the type of matrixmaterial. Similarly, the water supply 26A supplies water at a controlledrate through a conduit 60 into the mixing station 58 so that controlledamounts of matrix material, seed and water or water solutions are mixedtogether at the mixing station 58 in a continuous process for thoroughmixing with the station 58 receiving at any one time between 1 percentand 60 percent of the total amount a batch to be processed during batchprocessing, or if continuous processing is used, a volume of properlyproportioned materials which is adapted to fit into a flow stream nofaster than the slowest processing of that stream. The proportionalmixtures are mixed at the station 58 and conveyed by the mixer, agitatorand transporting system 62 which moves the mixture along by a series ofpanels to an outlet where it may be conveyed to the seed conditioner.The seed conditioner may accumulate it batch by batch for processing orthe seeds may be conditioned in a continuous process.

In FIG. 5, there is shown a conditioner 14 which includes a means forcontrolling the temperature, moisture and oxygen supply of the matrixcontaining seeds to promote pre-germination conditioning. In theembodiment of FIG. 5, all of these functions are performed in a unitarymanner by a porous fabric bag 72 which contains the matrix and seeds, asuction manifold 74 positioned for even moisture and temperature drawingof air through the fabric bag 72 and matrix to a vacuum manifold 76 anda temperature and moisture controlled room for this processing. For verysmall amounts, the air drawing supply 74 is unnecessary since there willbe adequate natural transfer of heat and oxygen through the matrixmaterial for the desired purposes.

The fabric bag 72 has a open end for supplying the mixture to the bagand an openable bottom end for supplying conditioned seeds to atransport conveyor 80 after a conditioning stage. In practice, the seedsmay be conditioned in the fabric bag 72 and then transported for dryingback through a 10 percent stage of drying and then returned to the bagfor further conditioning. Moreover, the conditioning may extend untilthe beginning of emergence and inoculated and dried and conditionedagain prior to emergence.

To draw air through the fabric bag 72, a centrally located vacuum pipe74 extends downwardly. It is designed so that the larger surface area onthe outside of the fabric bag 72 pulls cool dry air through the widerarea, and as it picks up some heat and moisture, the rate of flowbecomes greater since it is moving inwardly through spheres of smallerarea to maintain uniformity of temperature through the bag and relativeuniformity removal of moisture. In the preferred embodiment, the bagsgenerally contain between 20 pounds and 1,000 pounds of mixture,contained in a room that is between 10 degrees Centigrade and 15 degreesCentigrade with air being pulled from a manifold under a vacuum pressureof a negative 10 pascals through an outer surface area of 75 square feetto an inner perforated conduit having a diameter of between 1 inch and15 inches and open pores and ends for drawing air having a combined areaof 75 square centimeters.

After a conditioning stage, the fabric bags 72 may be physically movedto driers and dumped into the driers in a manner shown herein or thebottoms may be opened and conveyor mechanisms 80 may convey the mixtureto driers or to a drying stage.

In FIG. 6, there is shown one embodiment of drying assembly 16 having abin assembly 90, a blower assembly 92, and in some embodiments a coverassembly 100. A source of air pressure 102 applies air through blowersor the like to the blower assembly beneath the bin assembly 90. The binassembly 90 has a fabric bottom through which the air pressure blows tocause turbulence in the matrix material spread across the bin assembly90 for drying thereof by air flow. A cover may be placed over the binassembly 90 to create slight negative pressure if desired for dustcontrol and moisture may be extracted by recirculation of the airthrough desiccators in the cover.

In one embodiment, air pressure in the manifold beneath the bin assembly90 of a positive 50 pounds per square inch is applied through a 60 gaugefabric for drying matrix material applied in a layer between 4 inchesand 3 feet deep and having a pressure on the fabric of between 6 ouncesand 15 pounds per square inch.

In FIG. 7, there is shown another embodiment of drying assembly having aplurality of drying towers 100A, 100B, and 100C each of which receives amixture of matrix and seed for drying with the seed being applied to thetop of the tower 100A through a conveyor 106A which may be an auger oran air blower or the like for filling the tower 100A. The tower 100A isemptied into the tower 100B through a similar conveyor 106A and so ondown the line until the drying operation is completed, after which themixture may be moved to a separator for sifting and separating or may bestored for use in a planter with the matrix material and seed combinedor moved to a location for chemical treatment or biological inoculation.Each of the towers is identical and so only the tower 100C will bedescribed.

To provide a stage of drying, the drying tower 100C contains an elevatedbin 102 having a plurality of stages of air flow conduits 104A, 104B and104C. Any number of such stages may be supplied and they include withinthem a blower for blowing air crosswise through the tower where it isreceived by the next section for blowing crosswise again through thetower from the opposite side forwardly so that the air blows across thetower through several stages, three being shown for illustration in FIG.7. A desiccant or other dryer may be utilized at each stage to removemoisture from the air as it dries the mixing combination.

In FIG. 8, there is shown one embodiment of separator for separating thematrix material from the seed. This embodiment includes commercialsifters with gauge shifting designed to hold the seed but permit thematrix to fall through or to hold the matrix and permit the seed to fallthrough or to sort the seed and matrix at two different slides orconveyors for convenient separation.

With this arrangement, seeds are primed using a solid phase matrix,rather than using aqueous solutions. The matrix comprises finely dividednon-plant-pathogenic, water-holding solids. Preferably, the matrixmaterial, not including the seeds, is in such proportion anddistribution with respect to the seeds so that the seed surfaces aresufficiently aerobic to: (1) favor aerobic metabolism of the seed and ofbeneficial microorganisms; (2) deter the growth of unfavorablefacultative anaerobes or anaerobic microorganisms; and (3) to permitproper metabolitic changes. In most cases, this is accomplished by usingthe proper volumetric ratio of seed to matrix material and aeration.

A slight modification of this equipment permits the screening out of badseeds. In this method, higher gravity or larger seed particles areeliminated by screens or agitating until the larger seed particles areremoved. In this specification "seed particles" means the seed andmaterial adhered to the seed by sticking to seed exudate. This processis a result of noticing that injured seeds exude more than healthy seedsand thus more matrix material or the like stick to them.

The solid matrix priming compositions described above can alsoadvantageously contain: (1) prescribed amounts of known seed fungicidessuch as thiram, captan, metalaxyl, pentachloronitrobenzene, andfenaminosulf, so that the finished primed seed is coated with or absorbsthe desired amount of fungicide, such as is known to those skilled inthe art; (2) microorganisms useful to the crop such as those useful incrop protection, stimulation or establishment, and for such purposes,some significant bacteria are strains of: Bacillus enterobacter,Pseudomonas, Rhizobia and Serratia species and some significant fungiare strains of Trichoderma, Gliocladium and Laetisaria species; (3)pesticides such as fungicides or bactericides included prior to, duringor after the solid matrix priming; and (4) growth regulators such aspotassium nitrate, gibberellic acid, DCPTA, ethephon.

In this specification, "solid matrix priming" is considered the processwhereby seeds are intimately mixed with particulate solid phase media inthe presence of sufficient water to realize a moisture content in theseed which allows for germination processes to occur but which preventsradicle emergence. During priming and especially during solid statepriming, the addition of chemical additives and microorganisms isespecially beneficial. In this specification, the language "addedbeneficial microorganisms" means a beneficial microorganism that isadded to the composition at a level in excess of that naturallyoccurring on the seed being primed.

In this specification: (1) threshold germination temperature range meansthat range of temperatures for a certain species within which seeds ofthat species will germinate at a predetermined moisture level and withadequate oxygen; and (2) threshold germination moisture range means thatrange of moistures for a certain species within which seeds of thespecies will germinate at a given temperature and with adequate oxygen.

In addition to the above ranges, the limiting points of moisture andtemperature in this specification are defined as follows: (1) thresholdgermination temperature base means that temperature below which a seedfor a given species will not germinate even though the oxygen andmoisture levels are acceptable; (2) threshold germination criticalmaximum temperature means that temperature above which a seed of a givenspecies will not germinate even though there is an acceptable moisturelevel and adequate oxygen; (3) threshold germination moisture base meansthat moisture level below which a seed of a given species will notgerminate even though the temperature and oxygen are appropriate; and(4) threshold germination moisture critical maximum level means thatmoisture level in soil above which a seed of a given species will notgerminate even though the temperature and oxygen are adequate.

Other convenient terms are defined as follows: (1) emergence rate indexmeans the sum of the emerged seeds, n, on each day multiplied by aquantity for that day, quantity for that day being equal to the totalnumber, c, of days in the assay minus the count, n, of seedlings on thatday; and (2) synchronization factor means the emergence rate index thatoccurs in the period that is one-quarter of the time into the totalassay period. The assay period is a normal field crop emergence period.The emergence rate index and synchronization factor can be calculatedusing seeds germinated instead of seedlings emerged to arrive at asimilar number. This may be called a germination rate index.

The above values are determined empirically for a given seed and varietyand may be used in planting.

A sufficient amount of matrix or a matrix of material sufficientlyadsorbent or absorbent to remove enough inhibitors to prevent delay ofmore than fifteen percent of the time duration of activation prior to acontrol time of germination in which the inhibitor is substantiallycompletely removed by an appropriate washing technique is required. Thetime of germination in this specification is that the visible radicleprotrusion can be observed and the activation period occurs whenmembranes become differentially permeable and conversion occurs fromsubstantially passive solute transport in and from the seed. The amountand type of matrix is also selected to either retain or permanentlyremove exudates so that: (1) in the case of removal, it is notdeleterious such as for example, to encourage pathogen growth; or (2) inthe case of retention, to enable growth of innoculated beneficialmicrobes on seeds.

The matrix priming process also provides a superior approach to SAR(Systemic Acquired Resistance) as described in "Systemic AcquiredResistance" by Scott Uknes, et al., in Hort Science, Vol. 30(5), August,1995, pages 962 and 963 and other publications. For example, using thisprocess, additives may be mixed with the seeds during conditioningdescribed above to induce immunity. Both pathogens and non-pathogens areable to induce immunity. Moreover, the known seed funigicides describedabove such as thiram, captan, metalaxyl, pentachloronitrobenzene,fenaminosulf and some growth regulators including those mentioned abovemay have this effect. Systemic acquired resistance is aided by theconditioning described herein, particularly when the matrix includeslignin. The priming process stimulates certain genes that causeresistance to pathogrens. This is sometimes referred to in theliterature as a "signal" that permits the induced immunity to somepathogens that are present at the time of the signal.

EXAMPLE

Seed-Solid Matrix--Water

Preliminary studies were conducted to determine the ratio of seed tosolid matrix to water for effective solid matrix priming (SMP). The goalwas to achieve a seed moisture content that would allow favorablepregermination activity and prevent radicle emergence for a particularcrop. This optimal ratio was determined on an empirical basis by mixingseed and solid matrix on a weight to weight basis. The water wascalculated as a percentage of the seed and solid matrix by weight. Theseed, solid matrix and water were mixed and incubated at 15 degreesCelsius in a closed container with a small hole in the lid forventilation. Results are shown for different crops in Table 1.

Moisture Contents and Water Relations of Humates and Seeds

Seeds of the five crops were primed in Agro-Lig as described in Table 1.Seeds were separated from the Agro-Lig by shaking through appropriatesized sieves. At the end of the priming treatment, the percent moisturecontent of the seeds in Agro-Lig was determined gravimetrically. Thematrix potential (psi-m) of Agro-Lig was determined as described byBlack (ed.), 1965, "Methods of Soil Analysis" Academic Press, N.Y., N.Y.The osmotic potential (psi-s) of the Agro-Lig was determined by thefollowing procedure. Four parts distilled water was added to one partAgro-Lig (wt/wt), samples from each crop to produce an extract(Greweling and Peech, 1960, N.Y. Agri. Expt. Station Bul. 960).

                  TABLE 1                                                         ______________________________________                                        The optimal ratio of seed-solid matrix for effective                          priming of different vegetable at 15 degrees Celcius.                         Solid   PARTS BY WEIGHT                                                       Duration                                                                              Solid              % (z)                                              Crop (day)                                                                            Matrix       Seed      Matrix Water                                   ______________________________________                                        Tomato  Agro-Lig(1)  1.0    1.5  95     6                                             Soft coal(2) 1.0    1.5  95     6                                             Sphagnum moss                                                                              1.0    1.5  90     6                                     Carrot  Agro-Lig     1.0    1.5  90     6                                     Onion   Agro-Lig     1.0    2.0  80     6                                     Lettuce Agro-Lig     1.0    2.0  85     1                                     Cucumber                                                                              Agro-Lig     1.0    1.5  60     6                                     ______________________________________                                         (z) Percentage water based on dry weight of solid matrix.                     (1) Total % organic 84%, less than 1% nitrogen.                               (2) Total % organic 90%, less than 1% nitrogen.                          

The liquid phase was filtered and the psi-s of the Agro-Lig solutionextract was determined with a Microsmettte model 5004 (Precision SystemsInc., Natick, Me.). The psi-s of Agro-Lig without seeds was alsocalculated to quantify the influence of seed leakage on the psi-s of themedium. The total water potential of the Agro-Lig was determined foreach crop after SMP with a HR-33 dewpoint microvolt meter and C-52sample chamber (Wescor Inc., Logan, Utah). Thus the total waterpotential calculated from its component fractions, psi-m and psi-s couldbe compared with the water potential measured by thermocouplepsychrometry. There were four replications per treatment for each study.

Seedling Emergence Studies

The influence of solid matrix priming (SMP) and other conventional seedpriming treatments was studied on seedling emergence and plant growth ingrowth chamber studies. SMP of tomato (Lycopersicon esculentum) `NewYorker` was conducted with Agro-Lig, soft coal and sphagnum moss (Table1). Other priming treatments included: -1.0 MPa PEG 8000 (Coolbear, etal., 1980, Seed Sci. and Technology 8:289-303) and 1.0% KNO₃ and 1.5% K₃PO₄ (Ells, 1963, Proc. Amer. Soc. Hort. Sci. 83:684-687). SMP of carrot(Daucus carota) `Danvers 126` was conducted with Agro-Lig (Table 1).Other priming treatments included: 25% PEG 8000 (Szafirowska, et al.,1981, Agron. J. 73:845-848) and 0.2 m KNO₃ +0.1 m K₃ PO₄ (Haigh, et al.,1986, J. Amer. Soc. Hort. Sci. 111:660-665). SMP of onion (Allium cepa)`Downing Yellow Globe` was performed with Agro-Lig (Table 1). Otherpriming treatments included: 34.2% PEG 8000.

All priming treatments were performed at 15 C for 6 days which, in manycases, is a modification of the original procedure described in theliterature. All priming treatments were prepared with 0.2% (wt/v) thiram(Gustafson, Inc., Dallas, Tex.) as a fungicide.

Seeds were rinsed and blotted dry after priming. Seeds were sown inflats filled with an artificial (Peat-vermiculite) soil media. Therewere four replications of 50 seeds per rep in a randomized completeblock design. Flats were maintained in growth chambers with 20 C day and10 C night with a 12 hour photoperiod. Seedling emergence was recordeddaily and the plant dry weight was determined at the termination of theemergence period.

Thermodormancy

Alleviation of thermodormancy by priming was studied in lettuce (Lactucasativa) `Montello`. SMP of lettuce was performed with Agro-Lig (Table1). Conventional priming treatments included: -1.5 MPa PEG 8000(Bradford, 1986, supra) and 1.0% K₃ PO₄ (Cantliffe, et al., 1984, PlantPhysiol. 75:290-294). After priming, seeds were rinsed and allowed todry. Seeds were placed to germinate on moistened blotters in closedcontainers. The containers were maintained at a constant 35 C in thedark. There were four replications of 50 seeds each and the percentgermination was determined after 10 days.

SUMMARY

Seed-Solid Matrix--Water

The solid matrix served as a reservoir for water and 1.5 to 2.0 parts ofsolid matrix were required per part of seed to allow effective priming(Table 1). The percentage of water added varied with crop and rangedfrom 60 to 95%. Despite the high initial water content of the mixture,the solid matrix remained friable and did not lose its structure.

Moisture Contents and Water Relations

Seeds of all crops were able to imbibe water from the Agro-Lig since areduction in the Agro-Lig moisture content was measured after SMP (Table1 and 2). At equilibrium all crops except for cucumber had a higherpercentage moisture content than the Agro-Lig (Table 2). The tresholdseed moisture content for priming varied with crop and ranged from 42 to24 percent (wet basis).

The components of the total water potential responsible for priming weredetermined. The water potential of Agro-Lig is the sum of the psi-s andpsi-m. The water potential of the medium varied with crop and rangedfrom -1.34 MPa for SMP tomato to -1.77 MPa for SMP cucumber. The psi-mcontributed only a small fraction of the total water potential andranged from 3 kPa for SMP tomato to 23 kPa for SMP cucumber. The psi-sdue to the Agro-Lig alone was responsible for the largest portion of thewater potential, however, additional osmotic effects was attributed tosolute leakage from seeds into the medium. Calculation of the Agro-Ligwater potention by its component parts overestimated (predicted a lowerwater potential than) the Agro-Lig, except in the case of the cucumber,as determined by thermocouple psychrometry (Table 2).

                  TABLE 2                                                         ______________________________________                                        The percent moisture content of Agro-Lig and                                  seeds after SMP. The total water potential of the Agro-Lig                    was determined by thermocouple pychrometry.                                           PERCENT MOISTURE CONTENT                                                        Agro-Lig Seed       Seed   Psi                                      Crop      (dry basis)                                                                            (dry basis)                                                                              (wet basis)                                                                          MPa                                      ______________________________________                                        Tomato    50       61         38     -1.1                                     Carrot    42       67         40     -1.2                                     Onion     38       73         42     -1.4                                     Lettuce   42       72         42     -1.4                                     Cucumber  35       32         24     -1.9                                     ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        The influence of seed priming                                                 treatments on tomato seedling emergence and growth.                                                             Dry wt.                                                  Emergence  T50       per plant                                   Treatment    %          (days)    (mg)                                        ______________________________________                                        Nontreated   87 b       13.0 a    4.25 c                                      Agro-Lig     98 a       9.1 c     8.36 a                                      Soft coal    95 ab      9.6 c     8.23 a                                      Sphagnum moss                                                                              95 ab      9.4 c     8.02 a                                      -0.1OMPa PEG 98 a       10.5 b    7.02b                                       1.0% KNO.sub.3 and                                                                         95 ab      9.1 c     8.16 a                                      1.5% K.sub.3 PO.sub.4                                                         ______________________________________                                         LSD (5%)                                                                 

Seedling Emergence Studies

Sowing tomato seeds from all priming treatments decreased the time to50% seedling emergence (T50) and increased the plant dry weight comparedto the non-primed control (Table 3). SMP with Agro-Lig and priming withPEG resulted in greater percent emergence, however, the PEG treatmenthad a higher T50 and less dry weight per plant compared to other primingtreatments. From this study and other experiments (data not shown),Agro-Lig was chosen for the solid medium for the bulk of the studies.

Priming carrot seeds with inorganic salts resulted in lower percentageseedling emergence (Table 4). Faster seedling emergence (lower T50) wasobtained from sowing SMP seeds with Agro-Lig. Sowing onion seeds afterSMP with Agro-Lig decreased the T50 and increased the plant dry weightcompared to all other treatments (Table 5).

Thermodormancy

The beneficial effects of SMP has already been shown by sowing cropsinto a cool soil environment. Short term priming treatments were alsostudied to alleviate thermodormancy in lettuce. Imbibing non-primedseeds at 35 C resulted in 1% germination (Table 6). Conventional primingtreatments and SMP with Agro-Lig were able to alleviate thermodormancy.

The attainment of a threshold seed water content is most important forseed priming (Table 2). The water potential of the medium is indirectlyrelated to the seed moisture content (r=0.75). Bradford (1986, supra)primed lettuce seeds for 24 hours in

                  TABLE 4                                                         ______________________________________                                        The influence of seed priming                                                 treatments of carrot seedling emergence and growth.                                                             Dry wt.                                                  Emergence  T50       per plant                                   Treatment    %          (days)    (mg)                                        ______________________________________                                        Nontreated   88 a       10.8 a    1.38 c                                      Agro-Lig     89 a       7.7 c     2.17 a                                      25% PEG      87 a       8.5 b     1.89 b                                      0.2m KNO.sub.3                                                                             73 b       8.1 b     2.02 ab                                     +0.1m K.sub.3 PO.sub.4                                                        ______________________________________                                         LSD (5%)                                                                 

                  TABLE 5                                                         ______________________________________                                        The influence of seed priming                                                 treatments on onion seedling emergence and growth.                                                              Dry wt.                                                  Emergence  T50       per plant                                   Treatment    %          (days)    (mg)                                        ______________________________________                                        Nontreated   99 a       11.0 a    2.16 c                                      Agro-Lig     98 ab      6.0 c     3.61 a                                      34.2% PEG    98 ab      8.2 b     2.93 b                                      0.2m KNO.sub.3                                                                             95 b       7.8 b     2.87 b                                      +0.1m K.sub.3 PO.sub.4                                                        ______________________________________                                         LSD (5%)                                                                 

                  TABLE 6                                                         ______________________________________                                        The influence of seed priming treatments on lettuce permination at 35 C.                  Treatment                                                                     duration        Percent                                           Treatment   hours           germination                                       ______________________________________                                        Nontreated  --              1 b                                               Agro-Lig    24              75 a                                              -1.5 MPa PEG                                                                              24              71 a                                              1.0% K.sub.3 PO.sub.4                                                                     20              71 a                                              ______________________________________                                         LSD (5%)                                                                 

-1.5 MPa PEG. The seed moisture content was ca 70% which is in closeagreement with our data (Table 2). Similar data has been reported forcarrot; seeds were incubated in -0.1 and -1.5 MPa PEG solution for 6days which resulted in seed moisture contents of 76 and 68% respectively(Hegarty, 1977, New Phytol. 78:349-359).

Results from the water potential components of Agro-Lig are veryinteresting. One would immediately expect that the major componentresponsible for water potential was psi-m which is attributed to thefact that Agro-Lig is similar to an organic soil. However, psi-m couldaccount for less than 1.5% of the total. The major portion of waterpotential is psi-s which is attributed to the Agro-Lig composition.Analysis of the Agro-Lig has revealed the presence of 10.2×10³, 1.84×10³and 1.187×10³ ug of calcium, magnesium and sodium, respectively per g ofmaterial.

Solute leakage from all seed kinds were found to contribute to thepsi-s. In a separate study, tomato seeds were leached for 6 hours andthen dried back to the original moisture content. SMP of thesepreviously soaked seeds resulted in radical emergence. Thus, the osmoticeffect of solute leakage from seeds during SMP does contribute to thewater potential of the medium.

Determination of the optimal ratio of seed-solid matrix-water wasperformed on a empirical basis. It must be understood in this systemthat, unlike priming with solutions, there is not a large portion ofsolid matrix to seed. Thus as seeds imbibe and leak solutes the waterpotential of the medium changes. A simple screening procedure is used toobtain the optimal ratio of matrix, water and additives for a particularseedlot. There are several factors that influence this ratio. Seedcharacteristics include: threshold seed moisture content, affinity forwater and the solute leakage. Agro-Lig characteristics include: innatechemical composition which influence the psi-s, the water holdingcapacity and water retention characteristics.

Seedling emergence and germination tests were conducted to evaluate thepromotive effects of the pre-sowing treatments. Conventional primingtreatments with PEG in inorganic salts were selected from theliterature. Treatment comparisons with liquid priming treatments couldbetter test the effectiveness of SMP. SMP with Agro-Lig wasstatistically equal to or better than conventional priming treatmentsfor improving seedling emergence, decreasing T50 and increasing plantdry weight (Table 3, 4 and 5). Thermodormancy was shown to be alleviatedwith either SMP or liquid priming treatments (Table 6).

It is not fully understood why SMP is superior to conventional liquidpriming treatments, however it is believed to be due to: (1) betteraeration; (2) less phytotoxicity; and (3) the availability of growthpromoting substances in the Agro-Lig. Humic acid is a naturallyoccurring plant growth regulator extracted from Agro-Lig (AmericanColloid Co.). Humic acid has been shown to stimulate seed germinationand seedling growth in carrot (Ricotta and Sanders, J. Am. Soc. Hort.Sci. in press). Seedling root and shoot growth has been promoted withhumic acid in wheat (Triticum aestivum) (Malic and Azam, 1985, Environ.and Exp. Bot. 25:245-252).

Similarly, it is not fully understood why synergistic results areachieved from the use of added microbes and chemicals during priming butsuch results are shown by tests, the results of which are provided inTables 7 and 8. The data in Table 7 demonstrate synergism with regard tosolid matrix priming and the utility of the technique in elicitingbeneficial stand establishment effects when used with beneficialmicroorganisms in addition to the effect of either treatment alone.Other tests show that the systemic when added to the solid matrixpriming system as well.

The data in Table 8 demonstrate that beneficial microorganisms actsynergistically with solid matrix priming in conferring standestablishment benefits. Seedling carried further show superiorresistance to damping off when treated with 1-102 in the solid matrixpriming system. The differential of 30 to 40% increase in emergence dueto treatment during priming has been found to be consistent. Similardata with beneficial pseudomonas, corynebacteria, enterobacter andbacillus species over a range of crops have been obtained.

The inoculation of seeds during matrix priming may be used as aninoculation system to introduce beneficial microbes into soil byinoculating seeds with beneficial microbes and permitting them to grow.In this specification, the words "beneficial microorganisms" or"beneficial microbes" means microorganisms inoculated by seeds and whichare any of those many microbes that: (1) have been identified inassociation with plant roots, soils and seeds and/or as endophytes anddetermined to result in growth substance mediated plant growthpromotion, improved plant nutrition and pest control through biocontroland/or improved plant health to have potential utility in agriculture;(2) have been identified or can be further selected or engineered fromthose already identified to degrade specific chemical agents in soils tohave potential utility in environment bioremediation if effectivelydelivered to the target site; and (3) are believed

                  TABLE 7                                                         ______________________________________                                        Effect of Serratia proteamaculans Strain 1-102,                               solid matrix priming and chemical seed treatment on Canola                    seedling emergence in Pythium infested soil.                                           Days After Planting % Emergence                                      Treatment                                                                              1        2     3     4   5     6   7                                 ______________________________________                                        Untreated                                                                              0        0     0     4   17    18  20                                SMP      0        0     0     3   10    13  15                                Vitavax  0        0     0     10  42    58  64                                1-102    0        0     0     8   38    52  60                                SMP +    0        0     0     21  50    62  67                                1-102 AP                                                                      SMP +    0        0     0     26  63    82  82                                1-102 DP                                                                      ______________________________________                                         SMP = solid matrix priming is calcined clay and pH 6.8 phosphate buffer.      SMP + 1102 AP = strain 1102 added to the seeds after SMP.                     SMP + 1102 DP = strain 1102 added during priming which was for a 3 day        period.                                                                  

                  TABLE 8                                                         ______________________________________                                        Effect of Serratia proteamaculans Strain 1-102,                               solid matrix priming and biological seed treatment on                         Cucumber seedling emergence in Pythium infested soil.                                  Days After Planting % Emergence                                      Treatment                                                                              1        2     3     4   5     6   7                                 ______________________________________                                        Untreated                                                                              0        0     0     0   0     0                                     SMP      0        1     10    20  23    22                                    1-102    0        0     1     2   8     8                                     SMP +    0        3     15    50  48    43                                    1-102 AP                                                                      SMP +    2        8     58    79  80    80                                    1-102 DP                                                                      ______________________________________                                         SMP = solid matrix priming is calcined clay and pH 6.8 phosphate buffer.      SMP + 1102 AP = strain 1102 added to the seeds after SMP.                     SMP + 1102 DP = strain 1102 added during priming.                        

to be useful in supporting and protecting somatic embryos (syntheticseeds) as a substitute for zygotic seeds to deliver geneticcharacteristics of species which cannot be handled as zygotic seeds orto propagate elite germplasm and hybrids that are not now possible. Theuse of somatic embryos is described in Cantliffe D J, Liu J R (1987),"Development of artificial seed of Sweet potato for clonal propagationthrough somatic embryogenesis in: Methane from biomass: A systemsapproach", Smith W H, Frank J R (eds) Elsevier, N.Y. pp 183-195.

Beneficial microbes in association with plants are ubiquitous in naturalsoil environments and serve useful functions in removing contaminantsfrom the ecosystems. Such beneficial microbes are described in JohnDavison, "Plant Beneficial Bacteria", Bio/Technology, pages 282-284 andChet, et al., "Mechanisms of biocontrol of soil-borne plant pathogens byRhizobacterial", D. L. Keister and P. B. Cregan (Eds.), The rhizosphereand plant growth, 229-236. However, with the exception of Rhizobium andBradyrhizobium genera, none of the many beneficial rhizosphere, soil orseed based microbes that have been identified has been extensivelycommercialized. The problem is not whether useful microbes can beidentified but the economic delivery of a reproducibly useful inoculumat the target site.

The potential utility of beneficial microbes in managed terrestrialecosystems for agriculture and environment bioremediation issubstantially dependent on delivering adequate numbers of targetedbeneficial microbes to the ecosystem site/niche where activity is neededat an economical cost.

However, it has been discovered that seed inoculation and the subsequentgrowth of the target microbe in the root environment provides aneconomical mechanism for delivering adequate numbers of beneficialmicrobes to a terrestrial environment. The bulk of the inoculum increasetakes place using photosynthesis as energy and the rhizoplane,rhizosphere or plant endosphere as the bioreactor site.

Numerous genera of plant growth promoting rhizobacteria (PGPR) have beenreported to have growth promotion and biocontrol activity (Schroth andHancock, 1981). Their review was over a decade ago and many otherreports have been made since that time. However, PGPR usually fail inthe field because of poor bacteria distribution on roots and failure oftheir antagonistic activity toward detrimental rhizosphere microbes(Schippers, et. al., 1987). It is generally believed that a criticalthreshold population of a particular PGPR must be established to beeffective and the method of application is critical (Weller, 1988). Thesolid matrix seed priming (SMP) process and a solid matrix seed primingbased microbial inoculation process (SMPI) which has been effective inestablishing large PGPR numbers on seeds and has resulted in effectiveseedling establishment in disease stress situations as shown in Table 10(Table 1, Eastin, 1987, Solid matrix priming of seeds withmicroorganisms and selected chemical treatment, U.S. patent applicationSer. No.07/440,470; Eastin and Harman, 1987, Biological control andsolid matrix priming, U.S. patent application Ser. No. 034,813). Thedata in table 10 are representative of results with Pseudomonasflourescens, Pseudomonas putida, Enterobacter cloacae and Trichodermastrains that have been tested. It can be understood from this table thatthere is a large differential achieved if bacteria are applied

                  TABLE 10                                                        ______________________________________                                        Effect of Allelix's Serratia proteamaculans strain 1-102                      and solid matrix priming on percentage cucumber seedling                      emergence in Pythium-infested soil.                                                         Days after planting                                             Treatment     1     2       3   4     5   6                                   ______________________________________                                        Untreated     0     0       0   0     0   0                                   SMP           0     1       10  20    23  22                                  1-102         0     0       1   2     8   8                                   SMP + 1-102 AP                                                                              0     3       15  50    48  43                                  SMP + 1-102 DP                                                                              2     8       58  79    80  80                                  ______________________________________                                         SMP = solid matrix priming in SMP media no. 2 and pH 6.8 phosphate buffer     SMP + 1102 AP = strain 1102 added to the seeds after SMP.                     SMP + 1102 DP = strain 1102 added during priming.                        

during priming as contrasted to after priming. It is believed thesuperior emergence response from SMPI under disease pressure as shown inTable 10 is a function of bacterial colonization of the seeds ascontrasted to the lesser response with equivalent numbers of the samebacteria applied topically.

The SMPI system is based on the concept that microbes function in natureas colonies and the SMPI process provides microorganisms the opportunityto grow and colonize on hydrated seed surfaces. Priming seeds and theprocess of growing microbes on seeds during priming synchronizes radicleemergence and seedling development better with microbial activity fromcolonies established on the seed. The large log increase in bacterianumbers in/on the seeds appears to mean that low inoculum levels canresult in large seed bacteria population if the proper inoculationsystem is used. This has large economic implications as inoculum can beincreased by growing on the seed per se.

To inoculate soil with a beneficial microbe of any of the typesdescribed above, seeds are primed by mixing with the seeds a particulatesolid matrix material and a seed priming amount of water, for a time andat a temperature sufficient to cause the seeds to imbibe sufficientwater to enhance resultant plant vigor but insufficient to cause seedsprouting wherein said mixture has a water potential between about -0.5to about -2.0 megapascals at equilibrium with said seeds and saidparticulate solid matrix material is nonpathogenicto the seeds and tothe beneficial microbes. The primed seeds are planted under conditionsnot within one of said threshold germination moisture range andthreshold germination moisture range for the unprimed seeds of the samespecies but within said range for the primed seed, wherein thebeneficial microorganism is grown on the seed and matrix during primingmatrix material and is planted with the seed and the seeds and soil areinnoculated with a beneficial microorganism. The priming process isselected to be suitable for the beneficial microorganism. Thus, aftercolonizing the seed and matrix, the beneficial microorganism is presentin colony numbers on the seed and carried to the soil.

In some cases, harmful agents can be destroyed or rendered ineffectiveduring priming by antibiosis. For example, Psuedomonas gladioli which isa fungistatic bacteria has been inoculated onto sweet corn seeds byintroduction in moisture during solid matrix priming and killed duringdry back and storage. It acted as a powerful fungicide againstPennicilium and Fusarium species, thus SMPI can serve as an effectiveseed treatment process as well as a vehicle for effective seed and soilbeneficial microbe inoculation.

While a preferred embodiment of the invention has been described withsome particularity, many modifications and variations in the preferredembodiment may be made without deviating from the invention.Accordingly, within the scope of the appended claims, the invention maybe practiced other than as specifically described.

What is claimed is:
 1. A method of preparing seeds for plantingcomprising the steps of:mixing with continuous aeration of seeds, aparticulate solid matrix material and a seed priming amount of water,for a time and at a temperature sufficient to cause the seeds to imbibesufficient water to enhance resultant plant vigor but insufficient tocause seed sprouting to form a batch of seeds, wherein exudate fromdamaged seeds and said solid matrix material adhere to damaged seeds ingreater amounts than to undamaged seeds; and separating damaged seedsbased on increased amounts of solid matrix material that adheres todamaged seeds and undamaged seeds.
 2. The method of claim 1 in which theseparated seeds are separated by weight.
 3. The method of claim 1 inwhich the separated seeds are separated by size.